Potential use of recycled construction and demolition waste aggregates for non- structural concrete applications

Construction and demolition waste (CDW) represents 1/3 of the weight of all-waste produced. Increasing their recycling and reutilization with recycled aggregates (RA) means closing the life cycle of construction materials. Research has been carried out on artificial aggregates from the exclusive crushing of structural concrete waste in selective demolitions (CDWRConc). This study analyses the use of recycled concrete as graded aggregate (GARConc) and in cement soil (CSRConc). The material complies with the requirements as a road base, although due to the low values of resistance to fragmentation these materials are adequate for use in sensitive road systems and other places such as urban roads and car parks. The sensitive road systems are infrastructures in places of great natural wealth and low traffic intensity, with an annual average of heavy vehicle traffic (AADTh) below 50 vhp/d. As soluble salt contents have been detected, additional waterproofing or drainage measures must be adopted to prevent water infiltration into the layers made up of CDWRHorm. Finally, the high initial values of UCS allow the temporary passage of light vehicles over CSRConc after 3 days.

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Characterization of recycled aggregates construction and demolition waste for concrete production following the Spanish Structural Concrete Code EHE-08

Construction and Building Materials ◽

10.1016/j.conbuildmat.2010.07.012 ◽

2011 ◽

Vol 25 (2) ◽

pp. 742-748 ◽

Cited By ~ 98

Author(s):

M. Martín-Morales ◽

M. Zamorano ◽

A. Ruiz-Moyano ◽

I. Valverde-Espinosa

Keyword(s):

Construction And Demolition Waste ◽

Recycled Aggregates ◽

Demolition Waste ◽

Structural Concrete ◽

Concrete Production

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Limitations on the Use of Recycled Asphalt Pavement in Structural Concrete

Applied Sciences ◽

10.3390/app112210901 ◽

2021 ◽

Vol 11 (22) ◽

pp. 10901

Author(s):

Salma Jaawani ◽

Annalisa Franco ◽

Giuseppina De Luca ◽

Orsola Coppola ◽

Antonio Bonati

Keyword(s):

Asphalt Pavement ◽

Recycled Concrete ◽

Construction And Demolition Waste ◽

Concrete Aggregate ◽

Recycled Concrete Aggregate ◽

Recycled Asphalt Pavement ◽

Demolition Waste ◽

Structural Concrete ◽

Recycled Asphalt ◽

Minimum Requirements

Recycled materials from construction and demolition waste, such as recycled concrete aggregate, recycled brick aggregate, or recycled asphalt coming from the milling of road/motorway surfaces, are the key for a sustainable production of concrete. This paper reviews in particular the use of recycled asphalt pavement (RAP) aggregates in the production of concrete for structural uses. An overview is initially presented to describe the different areas of use of RAP, its definition and the limitations imposed by codes and standards. Relatively to the experimental data provided by the literature, a comparison with the Italian minimum requirements is also provided. Lastly, the influence of RAP on the characteristics of concrete such as compressive strength, flexural strength, Young’s Modulus and a study of durability are presented to define the possible applications of RAP in structural concrete in relation to the current allowable percentage of substitution.

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Improving the Quality of Mixed Recycled Coarse Aggregates from Construction and Demolition Waste Using Heavy Media Separation with Fe3O4 Suspension

Advances in Materials Science and Engineering ◽

10.1155/2017/8753659 ◽

2017 ◽

Vol 2017 ◽

pp. 1-12 ◽

Cited By ~ 2

Author(s):

Heonchan Kang ◽

Seong-Hoon Kee

Keyword(s):

Absorption Capacity ◽

Separation Process ◽

Construction And Demolition Waste ◽

Dry Density ◽

Demolition Waste ◽

Structural Concrete ◽

High Quality ◽

Coarse Aggregates ◽

Concrete Cylinders

The primary objectives of this study are to investigate the feasibility of a heavy media separation process with magnetite (Fe3O4) suspension for upgrading the quality of mixed recycled coarse aggregates from construction and demolition waste (CDW) in Korea and to determine a range of effective operating density of Fe3O4 suspension for producing high-quality RCA acceptable to structural concrete applications. For the purposes, six 200 kg recycled coarse aggregates (RCAs) samples were collected from a conventional recycling plant in Korea. Subsequently, the samples were processed by a heavy media separation process using Fe3O4 suspensions with various densities from 2.65 g/cm3 to 2.40 g/cm3 with an interval of 0.05 g/cm3. Next, a series of tests was performed in the laboratory to evaluate properties of finished sink and float products from the HMS processes, including oven-dry density, absorption capacity, and physical durability. Furthermore, compressive strength of concrete cylinders (150 mm by 300 mm) made of the finished sink products from Fe3O4 suspensions with three different densities (2.4, 2.5, and 2.6 g/cm3) was tested in this study. As a result, it was demonstrated that the HMS process using Fe3O4 suspension with a density ranging between 2.40 and 2.65 g/cm3 was effective for upgrading mixed CDW RCAs in Korea to high-quality RCAs acceptable for structural concrete applications.

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Inclusion of construction and demolition waste as a coarse aggregate and a cement addition in structural concrete design

Archives of Civil and Mechanical Engineering ◽

10.1016/j.acme.2019.08.004 ◽

2019 ◽

Vol 19 (4) ◽

pp. 1338-1352 ◽

Cited By ~ 10

Author(s):

B. Cantero ◽

I.F. Sáez del Bosque ◽

A. Matías ◽

M.I. Sánchez de Rojas ◽

C. Medina

Keyword(s):

Coarse Aggregate ◽

Construction And Demolition Waste ◽

Demolition Waste ◽

Structural Concrete

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Construction and demolition waste applications and maximum daily output in Spanish recycling plants

Waste Management & Research ◽

10.1177/0734242x20904437 ◽

2020 ◽

Vol 38 (4) ◽

pp. 423-432 ◽

Cited By ~ 1

Author(s):

G Rodríguez ◽

IF Sáez del Bosque ◽

E Asensio ◽

MI Sánchez de Rojas ◽

C Medina

Keyword(s):

Construction And Demolition Waste ◽

Recycled Aggregate ◽

Daily Maximum ◽

Maximum Output ◽

Demolition Waste ◽

Structural Concrete ◽

Adoption Of Technology ◽

Daily Output ◽

New Applications

The pursuit of construction sustainability has driven the use of partially or wholly waste-based eco-materials. New applications are being sought for recycled aggregate (RA) to further the use of this material and ensure the survival of the construction and demolition waste (C&DW) industry. RA, currently used in the construction of pavements, fills and embankments and only incipiently to manufacture structural or non-structural concrete, is a mere 8.99% of the total aggregate extracted in EU countries where RA is produced. Against this backdrop, the utility of this study lies in the overview afforded of RA typology, the application of the product in bound or unbound materials, the pursuit of new applications, structural or otherwise, and the assessment of daily maximum output by C&DW recycling facilities in Spain. The findings show that irrespective of its origin, RA most commonly adopts the form of wet mix macadam, gravel or sand used primarily in unbound applications with only dubious quality standards. Plant managers contend that RA from clean waste can feasibly be used in bound applications that require higher-performance materials. Maximum daily output varies widely, with capacity under 200 t d-1 in 30% of the plants. One of the conclusions drawn is that the current business model is in need of revision, with an emphasis on aggregate quality control (certification) and the adoption of technology for separating out impurities, pollutants and undesirable materials to improve the quality of RA.

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